Loading a truck bed, such as on a pickup truck, sometimes involves heavy or unwieldy lifting in a situation where mechanized equipment is unavailable for the task. Such a situation might occur in a home or field environment. Such a case can be made for snowmobiles, four-wheeled recreational vehicles, boats, game carcasses, or camper-inserts, to name a few objects which are too large or too heavy for manual manipulation. Another case can be made for aggregated loads, such as firewood, shingle bundles, building blocks, or soil, fertilizer, or salt in bags, where lifting individual pieces one-at-a-time would be inefficient. In all cases, it is useful to stage the load at ground level and use a portable device to lift and transfer the load onto the truck bed.
A winch and cable system powered by a battery comprises an easily portable device to drag a load onto a truck bed. In U.S. Pat. No. 5,232,329 to Livingston, a snowmobile loaded onto a ground-level pallet is lifted by a winch at the end of a boom. The boom doubles as a platform which can be raised to lift the load and then lowered by hydraulic means to receive the load at an appropriate incline. The loaded platform is then further lowered into the truck bed. The platform and associated hydraulics, however, must be installed in the truck, rendering the bed thereby unusable for other purposes.
In U.S. Pat. No. 3,894,643 to Wilson, a boat is hoisted onto the rear of a pickup truck by means of a winch tugging against a pair of articulating brace members, said members braced against both the rear of the truck and the ground to scissor the load thereby upwardly. During the lift, however, the forces of the weight of the boat and the downward pull of the winch cable are collectively applied to the tail, or rearward-most part, of the vehicle. At the tail, in such an extreme position, the forces are applied against the suspension and the frame with damaging leverage. Additionally, lateral forces from the brace members and from the winch act at different elevations on the truck, thereby creating a force couple on the truck and the attached scaffolding, which would add stress to the truck and cost in overdesigned structure.
In U.S. Pat. No. 5,269,642 to Zoromski, a camper-insert with an integrated structure comprising a winch and cable system is elevated at one end to be partially supported by stiff legs. As the load is winched farther onto the stiff legs, the center of gravity shifts to tilt the structure against the tail of the pickup truck bed. Further movement pivots the load over the tail and into the bed while simultaneously lifting the stiff legs. In spite of the temporary supporting role of the stiff legs, they are ultimately rendered ineffective in preventing weight from being applied to the tail in a potentially damaging way. Furthermore, the structural elements for the pivot are integrated into the load and cause the camper to sit high in the bed. Lastly, the winch cables are dragged over the lower front chine of the camper and along the bottom creating both frictional resistance and wear on both the camper and the cables.
The present invention provides novel solutions for loading a truck bed without the need to for structure permanently installed in the bed, without using the tail of the bed as a fulcrum edge, and in a way that minimizes any offsetting structure so that the load rides as nearly flush to the bed as possible.